No you cannot use those courtesy phones to call the gate of your connecting flight - in fact, stopping to try to do that will only waste valuable time. Just high tail it to the inter-terminal Terminal Link train (which is within the secure area so no need to re-clear security) and get to your connection gate as soon as you can. If you have all your flights on the same ticket and miss the connection becasue of delayed arrival you will be accommodated n the next available flight.